HVAC systems are well known in both residential and commercial environments, and are typically utilized to maintain the environmental conditions within a closed space, such as a building.
A key component of any HVAC system is the ductwork within such a system. Known ductwork can take any particular cross-sectional shape, but is usually either square or round. The ductwork is substantially sealed against ambient environmental contaminants and interference, and often extends great linear distances when incorporated throughout an entire building, or complex of buildings.
As the ductwork threads its way throughout the superstructure of a given building, it is often necessary and desirable to have the cross-sectional size, or diameter, of the ductwork change at some point along its length. Changing the cross-sectional diameter of a round length of ductwork, however, is a cumbersome and time consuming task, given the present state of the art.
As known to those in the relevant art, there currently exists spiral pipe machines that manufacture variable lengths of round cross-sectional ductwork. These machines typically accept a flattened, metallic workpiece, and through a system of known rollers and metal forming components, these known machines output the finished length of round ductwork.
As noted above, the problem with these known spiral pipe machines is that production of the machine (including feeding of the web) must be stopped every time a different diameter of ductwork is desired. In addition to the lost productivity caused by shutting the machine down, it is also necessary in these known systems to manually change internal mandrels, and the like, in order to facilitate the change in ductwork diameter. Subsequent to the formation of a differing sized piece of ductwork, it then becomes necessary to manually join the two lengths of differing sized ductwork via a separately formed transition element. Thus, the known method and apparatus for altering the diameter of a given spiral pipe is time consuming, labor intensive and generally inefficient.
It will thus be readily appreciated that there exists a need in the art for a spiral pipe machine that reduces the time and labor involved in changing between different diameters of manufactured spiral pipe, or ductwork.
With the forgoing problems and concerns in mind, it is the general object of the present invention to provide a spiral pipe machine capable of automatically changing the diameter of manufactured round ducts without interrupting the operation of the spiral pipe machine.